Any way to get past writer's block?

Do practice stories and writer prompts.

If you don't have an idea you don't have a story and nothing to work on. So look up the many many many online websites where there are writing prompts and story ideas. Tweak them a bit to your liking and go practice.

Practice every day and also important READ. Reading will give you many ideas and insights in how things are done. What makes a character that is interesting? What makes a story move forward and how to make a villain that we as readers/moviewatchers hate. Or maybe we learn to love the villain hell that is even better at times.

By reading and watching movies you begin to pick up the subtle art of story telling. And with that you get more insight in what works and what doesn't works. If you find a book you don't like why don't you like it. It is because it isn't in your field of interest or is something very wrong with the book.

And while that keep on writing on those writer prompts.

If you get ideas write them down and keep them in a folder. If you get a great idea but don't know how to write it yet you still can save the idea and write on it later.

In the end writing is work so expect to put time into it before you get better.

Because your target is short film best is to hunt down those indie movie awards, you know those 20 to 30 minute movies show by students. And try to learn what drives these stories, these movies and methods they use.